The apartment is owned by longtime Giuliani buddy Howard Koeppel , according to neighbors in the building.Koeppel is a Queens car dealer and big-bucks mayoral fund-raiser who marched side by side with Giuliani in last weekend's Gay Pride Parade.

Asked about his special houseguest , Koeppel said , I'm not going to say no and I'm not going to say yes..

Koeppel did say he lives in the same apartment with his partner , whom he identified as Mark Hsiao.

Giuliani's office had no comment on The News' report , but a source close to the mayor confirmed he was spending nights away from Gracie Mansion and staying at the apartment of a close personal friend..The source would not confirm it was Koeppel , but another source acknowledged the mayor was sharing the pad with two other people.